A GPS jamming signal that has disrupted navigation across Europe, Greenland and Canada for years traces back to a Russian early-warning satellite designed to detect ballistic missile launches, according to a peer-reviewed study submitted this June. The finding, corroborated independently by a commercial satellite built to test resilient navigation technology, gives the clearest picture yet of a source that has puzzled GNSS researchers since 2019.
Six Years of Interference, Traced to One Satellite
Todd Humphreys, who leads the Radionavigation Laboratory at the University of Texas at Austin, published the preprint together with UT Austin researcher M. Clements and Stanford's Argyris Kriezis on 10 June, titled "Chasing Lightning: Detecting, Characterizing, and Identifying a Powerful Space-Based GNSS Interference Source." The paper, submitted to the Institute of Navigation's NAVIGATION journal, documents 75 separate interference events recorded between January 2019 and April 2026, each producing a simultaneous drop in GPS signal strength across a wide swath of the Northern Hemisphere, SpaceNews reported. The researchers identified the pattern by cross-referencing dips recorded at ground stations thousands of kilometers apart and matching the timing to the orbital track of a single spacecraft.
The signal traces to Cosmos 2546, one of three satellites in Russia's Edinaya Kosmicheskaya Sistema (EKS) constellation. EKS satellites fly in highly elliptical Molniya orbits and exist to detect missile launches and nuclear detonations for Russia's early-warning network, GPS World detailed. The interfering signal registers hundreds of times stronger than a normal GPS transmission and sits directly on the L1 frequency band used by most civilian receivers. It degrades China's BeiDou constellation the same way, a pattern researchers say has been present since June 2020, while leaving Russia's own GLONASS system untouched entirely. The authors describe that selectivity as too consistent to be equipment malfunction, even if the study stops short of confirming Russian government intent.
An Independent Confirmation From Low Earth Orbit
The Humphreys team's ground-based findings arrived alongside a separate discovery made from orbit. Xona Space Systems, a startup building a low-Earth-orbit alternative to GPS called Pulsar, switched on a GPS receiver payload aboard its Pulsar-0 demonstration satellite, launched on SpaceX's Transporter-10 mission in March 2024. Operating roughly 500 kilometers up, the satellite mapped the same jamming pattern over Europe and the Middle East, Space.com first reported. Co-founder Kaz Gunning said the scale of what the satellite recorded was "quite a bit more than we expected," underscoring that interference strong enough to reach orbit is no longer a theoretical risk confined to ground receivers.
Regulators Are Moving Faster Than the Jamming
Aviation regulators have been tracking the broader jamming and spoofing trend for years and are now updating guidance in response. The European Union Aviation Safety Agency issued the fourth revision of its Safety Information Bulletin on GNSS outages and alterations on 3 July, the product of a joint task force EASA runs with Eurocontrol, Runway Girl Network reported.
The International Air Transport Association has reported a 175 percent year-on-year rise in GNSS interference events affecting flights in 2024, a trend it has called safety-critical for airline operations, aviation outlet Nairametrics reported.
The episode carries a lesson beyond aviation. Positioning, navigation and timing signals underpin satellite ground segment operations, from antenna pointing to the time synchronization that keeps SATCOM networks and terrestrial infrastructure aligned. Xona's own response, building signal authentication directly into its Pulsar payload rather than relying on GPS's unencrypted civilian signal, reflects a broader shift among PNT providers toward cryptographically verified navigation as the baseline defense against exactly this kind of interference.
For satellite operators and ground segment providers, the takeaway is that GNSS interference is no longer confined to conflict-zone airspace. A signal broadcast from a military satellite in Molniya orbit can degrade navigation as far away as Canada, and a commercial LEO satellite has now shown that the same interference is visible hundreds of kilometers above the jammed receivers themselves.
News first reported by SpaceNews and GPS World.
